Magnetically coupled control for cooking platform

ABSTRACT

A magnetically coupled type of control for a cooking platform has a movable support member for the magnetic follower in which the support member has a rack gear on one side for engagement with a rotatable pinion gear on a shaft of the thermal cycling switch, and with the other side of the support member having a channel receiving the straight portion of a guide bar and a pair of opposite open-ended slots to accommodate the ends of the guide bar in the rectilinear movement of the support member, with the secured ends of the guide bar serving as opposite end limits to movement of the support member.

Dec. 3, 1974 United States Patent 9 McCleerey et al.

3 9 004 Mmm 13W 33 2,745,027 5/1956 Wi11iford............... 3,634,802 l/l972 1 MAGNETICALLY COUPLED CONTROL Aldous..,...............,

FOR COOKING PLATFORM 3,711,672 I l/1973 Moreland et a1 3,796,850 3/1974 Moreland et a1.

[75] Inventors: Earl W. McCleerey, Monroeville;

William A. English, Export, both of Pa.

Primary Examiner-Bruce A. Reynolds Attorney, Agent, or FirmEl C. Arenz Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

Mar. 27, 1974 Appl. No.: 455,158

ABSTRACT A magnetically coupled type of control for a cooking '22 Filed:

platform has a movable support member for the magnetic follower in which the support member has a rack gear on one side for engagement with' a rotatable pinion gear on a shaft of the thermal cycling switch, and with the other side of the support member having a channel receiving the straight portion of a guide bar and a pair of opposite open-ended slots to accommo date the ends of the guide bar in the rectilinear movement of the supportmember, with the secured ends of [56] References Cited UNITED STATES PATENTS the guide bar serving as opposite end limits to movement of the support member.

Brenner 5 Claims, 3 Drawing Figures PATENTL B 3 I974 SHEET 10F 3 MAGNETICALLY COUPLED CONTROL FOR COOKING PLATFORM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains particularly to magnetically coupled controls useful with counter-top cooking platforms.

2. Description of the Prior Art.

The closest prior art of which we are aware is U.S. Pat. No. 3,711,672 in which a rack gear positioned between two pinion gears moves with the magnetic follower, with the two pinion gears controlling a potentiometer and an on/off switch in accordance with their rotation. The arrangement of the subject invention is considered an improvement thereover in several respects including that of reduced cost and being adapted to use a thermal cycling switch and a return spring arrangement. The subject arrangement is also adapted for use on either the right or left end control panel areas with the follower member being adapted to be positioned in either one or another laterally separated locations during assembly of the control to accommodate either a right or left-hand side arrangement.

SUMMARY oF TIIEIN'vEN IoN In accordance with our invention, the magnetically coupled control includes a user-operated control member on the accessible side .of a control panel, a magnetic follower member on .the other side of the panel, a support plate adapted to support two individual controls, an energization controllermounted to the support plate and having a rotatable shaft carrying a pinion gear, a guide bar mounted at its ends to the plate and having a straight length portion extending in both directions beyond the pinion gear, a support member for the follower including a rack gear on one side for engagement with the pinion gear and having an oppositely disposed channel-shaped section receiving the straight length of the guide bar and a pair of opposite, open-ended slots accommodating the endsof the guide bar inflthe rectilinear movement of the support member, with the guide bar ends serving as opposite end limits to movement of the support member, and means for mounting the follower member onv the support member to constrain movement of one relative to the other in a plane parallel to said support plate while permitting relative movement in a direction perpendicular to that plane.

DRAWING DESCRIPTION a FIG. 3 is an exploded isometric view,'partly broken and sectioned, to illustrate details of the arrangement.

DESCRIPTION o TIIE PREFERRED I EMBODIMENT As shown in FIG. 1,. the cooking platform as viewed from aboveiessentially comprises a generally perimetric frame of relatively thin,su'bstantially non-magnetic material such as aluminum or a 300 series stainless steel, with a glass ceramic plate 12 occupying a central opening of the frame and provided with visual indicia 14 for indicating the cookingareas and underlying locations of the heat producing elements 16. The useroperated control member 18 for each cooking area is located in a control area 20 of the control panel at the right and left-hand sides of the frame 10.

An individual control system is provided for each of the cooking areas. Each control system includes the control member 18 on the upper or accessible side of the control panel, a follower member 22 on the under or other side of the control panel, a support member 28, and an energization controller such as a thermal cycling switch mounted to the plate and having a pinion gear 30 on the upwardly projecting shaft of the thermal cycling switch.

As may be best seen in FIG. 1, a single support plate 28 is provided for each of the control panels at the right and left-hand sides of the frame, and two individual control assemblies are associated with each of the support plates. The support plate is provided with slotted holes 36 at those locations at which the plate is secured to a supporting box 34 (FIG. 2). This permits the support plate'to be shifted longitudinally before securement to obtain correspondence between the control I energization level indicia 37 on the control panel and the position of the underlying. control mechanism. It will also be noticed from FIG. .lthat the support plate 28 and the individual control assemblies are not in mirror image relationship to each other onthe right and left-hand sides, but rather that any given support plate with the control assemblies may be used on either the right or left-hand side without turning them end for end. This is possible with the arrangement according to the invention because the follower member 22 maybe shifted laterally on the'support member to either of two alternate positions, as will be further explained later.

Referring to FIGS. 2 and 3, the control member 18 and the followermember 22 may be of the same general structure and have magnetic blocks therein as described inthe noted U.S. Pat. No. 3,711,672. As there taught, as the control member is moved-along the control panel 20 in the direction indicated by the arrows in FIG. 3,,the follower .member 22 will correspondingly be moved in the same direction with the wheels 32 of the carriage of the follower member riding against the underface of the panel.

' the cook top. In either case, the posts are received in.

The support member 24, upon which the follower member seats, is formed of two separate plastic parts, an upper part 38 and a lower part 40 which are coextensive in length. The upper part includes a block 42 or bosses 48 on the underside of the follower member 22 are adapted to be received in either one or the other pairs of the bores, depending upon whether the control assemblies, are at the right-hand or the left-hand side of those bores which are toward the outer side of the cook top. Thus, in FIG. 3, the posts are received in the bores 46 indicating that this is the left side of the cook top. The posts are loosely received in the bores so that,

while the follower may move upwardly relative to the block 42, lateral movementof thefollower relative to the block 42 is not permitted. This'arrangement permits the carriage to move up solidlyagainstthe under- I 1 side of the control panel whenthe eontrol-"mernber 18 is in place.

Both the upper and lower 'parts 38 and 40lo fthe upport member are molded acetal plasticparts toprovide low friction contact surfaces.,The loweppart 40 includes a rack gear 50 along oneside' and includes a base flange 52 on its other side provided with tw op"- posite, open-ended slots 4 with an intermediate web 1 or land 56. These opposite, open-ended slots in the base flange portion ofthe support member accommodate the right angle end portions 58 0f the guide bar 26 during the rectilinear movement of the support memher from one extreme position to the other-, 'with the v end portions serving as stops for the support member when the land 56 abuts the end portions 58 of the guide bar. i The underface of the top part 38'of the support member is provided with a downwardly open channel which port member in the assembled relation of these parts. These parts 38 and 40 are held together in their assembled relation by the screws 60 and nuts 62. l

, With the upper and lower parts 38 and 40 of the support member assembled, the straight length portion 26 of the guide bar is in effect capturedin the channelshaped space 64 on the one side of thesupport membet, with the other side of the support member being held in position by the engagement of the pinion gear 30 with the rack gear 50. i

' The thermal cycling switch 66 may be of the general type shown in eitherU.S. Pat. No. 2,813,173 or 3,634,802, these being conventionalswitches for controlling energization of heating elements and are sometimes referred to as infinite switches. The upwardly projecting D-shaped shaft 68 of the. infinite switch receives the pinion gear 30 thereon and a spiral return spring 70 is provided with one end attached to the pin seats'upon the top face of the lower part 40 of the sup--14 distance from'lthe edge ofa'ny heating" ion gear and the other end attached to the support plate I 28. Thus, as the pinion gear is. rotated inthe direction of the arrow in FIG. 3tby the movement of the support member 24, thelreturn bias of the spring 70 is increased. However, the return force of thespring is not sufficient to overcome the ,friction between the control member "18 and the top panel created by the magnetic attraction betweenthe control member and thefollower member. However, if the control member 18 is removed from the control panel, the return spring will rotate the pinion gear and infinite switch shaft in a clockwise position, forcing the support member 24 back to the extreme position shown in.FIG.3. This, of course. corresponds to the infinite switch'being in an.

Off positionand deenergizationof the heating element.

- The arrangement as 'clescribed results in a relatively' lowfrict'ion load so that, if the magnetic coupling is broken by removing the control member 18, 'heparts will return to the Offposition. The low friction load exists because the guide bar 26 offers relatively little resistance to movement of thesupport member 24; and the fit of the support member to the guide bar and the pinion gear 30 is relatively loose. Also, thelthermal-cyclingswitch has a relatively low internal friction asconk trasted to a potentiometer. I

The relatively Ioose seating of thexcarriage on the suppo yt member permits thecarriag'etorise slightly in s -.magnetically coupled relation to the control memer to compensate for manufacturing tolerances in the vertical spacing between thes upport plate and the control panel. 3 l

Inthe assemblyof the parts,- the thermal cycling switch 66. is oriented to an Off position by the location ofhthe flat on the D-shaped shaft and withthe spring in a preloaded condition before the rack/gear 50 of the support member 24 is engaged with the gear 30.With one end of the. guide bar'26"loosened, the support member 24 is' moved to the extreme position at which the land,=5,6 abuts the other end 58 of the guidebar as 7 shown iiizFIG. 3, and the support memberis then swung 'tolplace theigr'ackxg'ear into engagement with the pinion 1 gear. Then, theiloese end oflthe guide bar is moved "over and secured t jli old theengagement between the rack gear and the pinion gear. The slotted holes 36 in the supportiplate 2Qpermit1the final adjustment of the I support plate'28 .to be macl efto, provide the proper registr'y between the switch Offpostion-and the position of the'control member l8 o n control panel a The arrangement, wh' h permitsijthe shifting of the carriage 2 2 laterally to eith'erjithe one pair of bores 44 or the other-pair 46,- accommodates the lateral registry of the eontrolass'embly with the control member 18 at 1eithersidei This iscohsidered adva' ittageousiiin connection with proposedstandajrfds which "require aminimum' locationof any control elernent f 1-. In a magneticallyicoupled type of arrange ment' for a cookingplatfoi'm having a, heat producing i 3 element a user-operated control member on themes l e side of acofntroLpanel; i

a follower 'rnember on the-other s ide ofisaid panel adapted tobe magnetically coupled to said contrql member;

a support plate .spaced from said other side of said];

, panel;

a controllerfor controlling energization ofs'a dheat producing elementfmounted tosaid supportplate and'including a rotatable shaft-projecting there-{Q from and having apinion gear fixedthereon; a guide bar mounted at itsends'on' said plate'and having a straight length extending on; both directions beyond said gear; and

a ,support memberfor said follower member having means for mounting said follower' member on said support member to'constrain movement of one fer; ative to the other in a-plane'parallel-tosa id support platewhile'permitting relative move' ent in a'di-' rectionperpendicular tojsaidplanef 3. In an arrangement according'to claim 1 including:

means biasing said pinion gear and controller to a deenergized position. 4. in an arrangement according to claim 1 wherein:

said support plate includes slot means for securing said support plate in one of a number of longitudinally shifted positions to facilitate proper registry of said control member with indicia on said control panel.

5. In an arrangement according to claim 2 wherein:

tioning of said follower member relative to said support member. 

1. In a magnetically coupled type of control arrangement for a cooking platform having a heat producing element: a user-operated control member on the accessible side of a control panel; a follower member on the other side of said panel adapted to be magnetically coupled to said control member; a support plate spaced from said other side of said panel; a controller for controlling energization of said heat producing element mounted to said support plate and including a rotatable shaft projecting therefrom and having a pinion gear fixed thereon; a guide bar mounted at its ends on said plate and having a straight length extending on both directions beyond said gear; and a support member for said follower member having a gear rack on one side for engagement with said pinion gear, and provided with a pair of opposite, open-ended slots on the opposite side to accommodate the ends of said guide bar in the rectilinear movement of said support member, said guide bar ends serving as opposite end limits to movement of said support member.
 2. In an arrangement according to claim 1 including: means for mounting said follower member on said support member to constrain movement of one relative to the other in a plane parallel to said support plate while permitting relative movement in a direction perpendicular to said plane.
 3. In an arrangement according to claim 1 including: means biasing said pinion gear and controller to a deenergized position.
 4. In an arrangement according to claim 1 wherein: said support plate includes slot means for securing said support plate in one of a number of longitudinally shifted positions to facilitate proper registry of said control member with indicia on said control panel.
 5. In an arrangement according to claim 2 wherein: said means for mounting said follower member on said support member includes a pair of projecting posts on said follower member and two pairs of post receiving bores on said support member, one pair of said post receiving bores being laterally offset from the other pair to permit alternative positioning of said follower member relative to said support member. 